Castings
Zirconium and hafnium metallurgy

Molded parts are not generally used in nuclear applications, but mainly for corrosion resistance applications in the chemical industry. Again, the high reactivity of liquid Zr represents the main difficulty: all refractory oxides, such as SiO₂, Al₂O₃, MgO, BeO, are reduced, ZrO₂ is dissolved, graphite is acceptable but with superficial dissolution in the metal. The simplest method of sand casting can therefore not be used. Early castings were made with machined graphite molds lined with suitable poteyages. Today, two main methods are used.

• The graphite mold is made...